精恶唑禾草灵对不同品种柴胡茎秆力学特性的影响

Effect of Fenoxaprop-P-Ethyl on Mechanical Properties of Different Chinese Thorowax Root Stem

为应用茎秆生物力学性质指标研究不同剂量除草剂对柴胡安全性的影响,以南柴胡和北柴胡茎秆为试验材料,精恶唑禾草灵为试验除草剂,分别在拔节期和开花期利用非金属材料万能试验机对茎秆基部第2节间的最大荷载、应力、应变、弹性模量、拉伸强度、剪切强度等力学指标进行测定和统计分析.结果表明:北柴胡的茎杆直径、最大荷载、抗拉强度等均高于南柴胡,最大荷载高了约13%,抗拉强度与茎杆直径呈线性相关关系(R=0.9194);南柴胡和北柴胡拔节期的茎杆拉伸强度和剪切强度均高于开花期;柴胡茎经中低剂量(0-1500ml/hm^2)的精恶唑禾草灵处理后,其抗拉强度和剪切强度无明显变化,但高剂量(3000ml/hm^2)的精恶唑禾草灵施用后显著降低了柴胡茎杆的抗拉强度和剪切强度,会直接导致柴胡抗倒伏能力降低,造成柴胡产量和品质下降.该结果可为柴胡田除草剂的安全施用及药材机械化收割技术的研发提供参考依据.

In order to study different doses of herbicide on the secure effect of bupleurum by using biomechanics properties of stems. This experiment was conducted by using B.scorzonerifolium and Bupleurum chinense as test materials, fenoxaprop-p-ethyl as herbicide. Section two of the base of stem was tested by using non-metallic materials universal testing machine, and the machani- cal properties such as maximum loads, stress, strain, young＇s modulus,tensile strength and shear strength were studied with statistical software. The results showed that stem diameter, maximum loads and tensile strength of Bupleurum chinense is higher than the B. seorzonerifolium, and the maximum loads of Bupleurum chinense is 13~ higher than the B. scorzonerifolium. The tensile strength showed a linear correlation of the stem pole diameter（R = 0.9194）. The tensile strength and shear strength with bupleurum stem in jointing period are higher than the flowering period. The tensile strength and shear strength have no significant effect after the bupleurum treated by low doses （0-1500ml/hm2） of the fenoxaprop-P-ethyl, but the tensile strength and shear strength of bupleurum stem are reduced sharply after using the high dose （3000ml/hm2） of fenoxaprop- P-ethyl, which can reduce the capability of resistance to lodging, and the quality and yield are decreased correspondingly. The result can provide reference for the safety application of herbicide on the bupleurum field and harvest medicinal materials with mechanization.